An indicator light conventionally comprises a filament lamp mounted on a back plate which constitutes its base, together with an optic or cover glass in front of the lamp. Optical means are frequently used for directing a major proportion of the light emitted by the lamp into a direction which is close to a preferential emission axis, or else to confer a homogeneous light intensity on the lighting field of the indicator light in the event that a light source is used which is essentially a light source giving an intense light output.
It is also known to provide an indicator light which is subdivided into a plurality of elements, each of which includes a small filament lamp, for example a lamp of the wedge base type, in cooperation with its own optical means, the object of this being to obtain a field of/light which is both homogeneous and of large extent, while the light unit itself is of reduced thickness. Such a light, having a plurality of lamps, is however expensive to make.
More generally, the various components of an indicator light, with the exception of the lamp or lamps (which are generally standard) must be subjected to scrutiny and specific development (in every case, in accordance with a given specification). This results in a relatively high selling price.
Other disadvantages of conventional indicating lights or light units lie in the fact that the filament lamps which are used have to be replaced quite frequently, and they generally occupy a substantial depth, due to the fact that the base on which they are fitted must present (at least with some lamps) a parabolic profile for light flux concentration. Yet another disadvantage is that it is impossible to produce fields of light with complex contours. In connection with this last point, the designer generally has to work with simple circular or rectangular shapes only.
The present invention aims to overcome the above mentioned drawbacks by providing an indicating light unit which can be made easily and inexpensively, with a light field having geometric and photometric characteristics which can be very freely determined, with the additional advantages that the thickness of the indicating light unit is extremely small, while the unit is highly reliable, all due to its modular design.
According to the invention, an indicating light unit for a motor vehicle is characterised in that it includes:
a support plate; PA1 an optic extending along the said plate; PA1 a plurality of elementary luminous modules each of which comprises a plurality of light emitting diodes mounted on a frame and covered by a cover element, with each said module incorporating electrical connection means for interconnecting the various light emitting diodes; PA1 fastening means for fastening the said modules in juxtaposed relationship with each other in predetermined positions on the said plate; and PA1 means for the electrical connection of the luminous modules to a common electrical supply source.